Fluorine resin has a number of features including excellence in chemical stability and thermal stability, and a low coefficient of friction attributable to its self-lubricating nature. However, fluorine resin is very costly compared to other resins for general purpose use, and the expensiveness has limited its uses in spite of the superior characteristics.
Furthermore, while fluorine resin exhibits chemical stability, contrarily it has presented difficulties in laminating a sheet- or film-shaped fluorine resin to a different material by an adhesive with the aim of reducing the amount of use. This has precluded the use of fluorine resin in applications for which the chemical stability can be exploited, for example, a stopper of a medicament container.
With this in view, as an attempt to render fluorine resin adherable to a different raw material by an adhesive, there is proposed a technique for improving an affinity for water, or hydrophilicity at the surface of a molded body of fluorine resin by performing surface roughening treatment on the molded body through plasma irradiation and substituting implanted plasma ion atoms for fluorine atoms of the surface of the molded body (refer to Patent literature 1).